I don't know if you can get that to work by just pressing one button. Normally you would hold the ALT key and press the ESC key to open the Application Switcher, and then while still holding the ALT key you could use the trackball to scroll to the app you wanted and then let go of the ALT key to switch to the app.

I just started using the application switcher and notice that BB Messenger and the Browser are in the list even though I haven't used either program in a long time (in fact I've never used Messenger). I have turned the Pearl on and off a few times and pulled the battery to reset the device a couple times as well since using the Browser last. Are these programs always running? Any way to shut them down? Are they eating up memory by running in the background?